I've no doubt there's some truth in the idea that many standard zooms perform at their best in the mid range and at middle apertures.

I think the problem then with them is that they are probably used more at either extreme end than in the middle - so not at their best at all. This is because we really actually need something longer and shorter than the zoom provides, so we end up just going to the maximum the zoom provides and accepting that - but its a compromise really, but in focal length choice and aperture possibly.

I have seen significant ca, mainly purple or blue fringing, on backlit edges with both my 28 f.2.8 and tamrom 135 f2.8. In all other respects the lenses perform brilliantly. But I very much doubt if I would ever have considered these aberrations as a problem had I used the lenses on a film body. At most print sizes I probably wouldn't have even noticed it.

No, I didn't use those sub 100 films. I see your point about the resolution comparisons (although no doubt a debate on the comparative 'resolution' of film stocks and modern sensors would run for a few pages (! ). But is it not the case that we were less likely to be aware of the lens IQ defects, even on high quality ISO 50 film, due to the re-production of that film - both in output quality terms and the limited size of the prints?

Looking forward to see the results from that shoot Steven. Have you got a wide angle (like a 14 or 15) to see how the software deals with edge distortions?

Regarding the very old lenses, is there not an increasing concern and risk about various IQ issues such as chromatic abberations and bokeh quality, especially on our newer and incresingly high resolution sensors?

You can keep on trying to break my love affair with the K7, but it will be in vain ... where matters of the heart are concerned.......

You won't even get me to buy a K3 - I mean, it doesn't even have a lever to switch between Af.S and AF.C ... practically unusable! And lets not start on with all that IQ and noise performance stuff, really, what does all that matter ....

I suppose the really important thing is not so much the exact numerical value of any processing correction, but rather how well the image responds to the processing - how easily the noise disappears and what after-effects remain.

Each different model may not have the same starting points (numerically) for any given processing parameter, or the reduction effect may not kick in until further up. I woudn't be concerned if the K3 needed 35 or 40 of ACR colour noise reduction, so long as there was no increased artifacts as a result of that input.

I'd question any assertion that if you need more NR input numerically for a particular sensor / camera model then the noise performance of that camera must be inferior. As I discovered with the K5II/s comparisons, actual pixel data responds differently and at different amounts of adjustment when the starting point of that data is different.

We benefit from amazingly lengthy backwards compatability, thats true, but maybe the stage has been reached where it may not be worth the effort bothering with the very old (adaptor required) lenses, at least not at the cheap end.

I still think the quality 'A' style lenses are incredibly valuable, very robust and a pleasure to use. And for those focal lengths that we don't use so much, quality older items (such as the 'M' series type that need stop-down metering) can be very much worth the extra effort, if they provide better quality but great value access to those focal lenghts, or wider apertures than you'd get on your zooms.

I feel my own examples fall into this category for me - 'A' 28mm, 'M' 75-150, Tamron Adaptall 135mm (works like an 'M'). I wouldn't want to give any of these up for a modern zoom.

I think the alternative view is great, on the first one its a bit like what you see when you're riding on an old steam train leaning out of the window taking shots towards the engine as you're going around a corner (if you see what I mean ), and I like that effect. Here, because there's clearly a lot of stuff just outside the left edges, the impression is a bit cramped and cut off.

I'm not the one to lecture Alan on composition though , but I will mention one small technical point, at the risk of being howled down (I'll brace myself :wink - but I find the skies very 'dirty', in terms of luminance noise, and colour noise in the cloud shadows). I mentioned it on another of your shots Alan, and I find it annoying (personally). I'm well aware it may not be a priority to many people, but having very 'clean' skys is something I always try and achieve. I do feel it would help give these images that extra polish.

It depends on the actual speed of the moving water of course, but I think a 'middle ground' approach usually works best. I'm not a fan of those very smooth and blurred effects, but just enough to show the flowing motion is best I think. The range from say 1/4 to 1/20th would work in many situations I think.

With the aperture issue, it looks like the metered exposure requires a smaller aperture than the lens can provide. If you're hitting this limit and can't allow the exposure to be brighter (say if the highlights are already blown out) then the best option is to use filters to cut the light back - either a polariser or ND will do that, or even both together if needed. If you can allow the exposure to be brighter then dial in some + exposure compensation until the flashing f value stops and settles. You might be able be recover the highlights in RAW software if its not too much or too important part of the image.

But handholding at these shutter speeds, especially if you're balancing on rocks or crouching down near the water is always going to be a challenge, so if its just not happening then you'll have to compromise on the moving effect and increase the shutter speed,

Good luck trying with your water shots, and lets see some when you're ready!